FAQ - Molecular Monitoring

AirSentry II AMC Monitor

Question
What is Airborne Molecular Contamination (AMC)?

Answer

Airborne Molecular Contamination (AMC) is a non-particle gaseous substance that may have a detrimental effect on a product or process. According to SEMI F21-95, AMC is broken into four categories: acids, bases, condensables, and dopants. Surface Molecular Contamination (SMC) is the result of gas phase molecules (AMC) interacting with critical surfaces to form very thin chemical films, often altering the physical, electrical, chemical, and optical properties of the surface. "Acidic gas contamination is particularly insidious because of its reactivity with a number of other chemical species." This often occurs on surfaces that are very sensitive to contamination such as semiconductor wafers, optical components within photolithography process tools, read-write heads, and magnetic coated disks in hard disk drives. Acidic AMC includes but isn't limited to SO2, HF, HCl, Cl2, NO, and NO2.

For more information read Monitoring Airborne Molecular Contamination: a Quantitative and Qualitative Comparison of Real-time and Grab-sampling Techniques.